Flat tires can be inconvenient for vehicle drivers. Though some flat tire conditions, such as blow-outs or large punctures, immediately render tires unusable and in need of replacement, many flat tire conditions result in a slow leak needing a source of pressurized air to reinflate until service is available. While some aftermarket systems provide for portable pressurized canisters for addressing a tire leak, such systems can degrade over storage time such that when finally needed, they are ineffective. And even if effective, they may offer limited use.
In one approach shown by Chinese Patent CN2260016Y, the compressed air generated by a cylinder of an engine is used to inflate a tire. A mixed gas shut-off valve is provided to allow for pure air inlet into a cylinder, and a spark plug of the cylinder is replaced with a hose coupling the cylinder to a tire. Engine operation is used to direct compressed air from the cylinder to the tire.
The inventors herein have recognized the above noted, as well as additional issues with such systems. As one example with respect to CN2260016Y, a typical user may not have the ability to remove a spark plug from an engine and successfully reinstall the inflator hose without introducing contamination into the engine system. Further, a hose sufficiently long to reach between the engine compartment and all vehicle tires may be prohibitively long and susceptible to damage during use, rendering it useless. As another example, a reciprocating air pump comprising a plurality of moving components and valves may be costly and prone to degradation due to extremely intermittent use. In yet another example, use of an engine-driven compressor and reservoir may decrease engine output while adding weight and cost to a vehicle system. As noted above, relying on a pressurized canister requires the user to have a functioning canister on hand. Further, in the case where the pressurized canister includes sealant, the sealant may become ineffective if stored for a duration longer than manufacturer recommendations, and the messy residue left by the sealant may require prompt and professional repair of the tire and may damage tire pressure sensors.
The inventors herein have recognized that a portable pressure vessel (PPV) fillable by a forced induction system coupled to an engine can advantageously provide the functionality of an on-board air pump. And at the same time, specific engine control and operating procedures can be coordinated to enable increased performance and ease of use. In one example, the issues described above may be addressed by a vehicle system comprising: an engine; a forced induction system coupled to an intake passage of the engine; a drivetrain with a tire; and a portable pressure vessel releasably coupleable to the forced induction system via a connection port, and further releasably coupleable to the tire. In this way, a reliable source of compressed air can be provided on-board a vehicle in case of an emergency, without requiring heavy and costly air pumps, and without affecting driving performance.
As an example, responsive to an operator request for initiating fill of am on-board portable pressure vessel during an engine idle condition, a vehicle controller may display to the operator a plurality of instructions that include enabling the operator to couple the portable pressure vessel to a forced induction system of a vehicle engine at a designated connection point. After confirming that the operator has connected the PPV at the designated connection point, and upon further confirming that refilling conditions are met (for example, that the engine is at idle, the hood has been closed and the operator has returned to the driver seat in the vehicle), boost pressure may be actively increased by operating the forced induction system according to a predetermined cycle. For example, boost pressure may be increased by operating the engine at an increased speed and/or at a higher load. The boost pressure applied may be higher than necessitated based on operator torque demand. The generated boost (e.g., compressed air) is directed to the portable pressure vessel through a connection port in the forced induction system. Once the PPV has been sufficiently filled, the forced induction system may resume nominal operation, and instructions may be displayed to the operator to disconnect the PPV from the forced induction system and proceed with tire inflation.
In this way, an existing forced induction system of a vehicle system may be advantageously used as an emergency source of compressed air for inflating tires. By reducing the need for a dedicated, constantly activated air pump and reservoir system, significant cost reduction and component reduction benefits can be achieved while providing a simple, low-cost, and reliable solution for inflating tires. The portable pressure vessel may be configured to be small enough to be easily depressurized and conveniently stowed during non-use. By ensuring that the PPV is stowed in a depressurized condition, the pressure vessel is rendered inert when not in use. By performing the PPV fill function during an engine idle condition, vehicle performance is not affected during filling of the PPV using the forced induction system.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.